The primary purpose of this shared resource is to generate novel polyclonal and monoclonal antibody reagents, to assist investigators in characterization and optimization of these reagents, and to provide other technical assistance for antibody-related research. Availability of high quality antibody reagents is critical for understanding protein function in normal and neoplastic cells and tissues. We aim to provide antibodies to cancer center members in a timely manner at a reduced cost, relative to commercial custom antibody services. We can also provide an expanded range of services that are not generally available from commercial sources, so that more investigators without expertise or equipment for molecular cell biology or biochemistry can successfully generate and characterize custom antibody reagents. Our most commonly used services include the generation of rabbit polyclonal antibodies, purification and/or testing of polyclonal antibody, generation of mouse polyclonal antibodies, and the generation, purification, characterization and testing of mouse monoclonal antibodies. Other services that we have provided include production and purification of bacterially expressed fusion protein antigens, antibody isotyping, cryopreservation and storage of hybridoma lines, preparation of Fab fragments from existing antibodies, adaptation of hybridoma lines to serum-free culture and recovery of poorly frozen hybridoma cell lines from other sources.